| According to the experience of shallow seam mining and under the condition of shallow coal seam and near shallow burial layer,the surface landform of earth has more impact on coal seam mining and cheuches also affect the excavation of working faces.Meanwhile,it is undoubt that coal mining leads to relevant influnences as well,involving surface collapse and deformation,land subsidence and appearance of land cracks caused by overmining and another fact that in the areas where the coal seam is shallow,when the cracks produced by mining connect with the catchment areas of the cheuch,surface water permeates the mine along developmental cracks,which bring out mine fire,posing the serious threat on saftety production of mines.In consideration of the fact that the most working faces of XieGou mines are located on cheuch in mountains,it has the important practical value for the safety mining of this mine to do researches about the rules of the development of water flowing fractured zone and water control in cheuches.Based on the engineering backgrounds which is about 18112 working face of 8#coal seam in XieGou mine,this article is based on achievements the predecessors got and comes to a conclusion about the most likely time and likely position for water inrush,which provides reference about mining water control and perfect the measures of water control further using combined meathod between analog simulation and numerical simulation to study the rules of development of overlying water flowing fractured zone in cheuches and mining water seepage field.The result of research shows:?1?The article analyses the overlying rock features above 8#&13#thick coal seams in the shallow buried cheuches areas of XieGou mine,features of the land surface topography and the hydrogeological conditions and draw a conclusion that is there are7 pieces of developed gully networks featuring half leaf shape and the main source of water filling is meteoric water?surface water and so on.?2?Using analog simulation to analyse rules of development of overlying water flowing fractured zone under the definited situations.This meathod shows that with8#18112 working face going forward,there is large-scale caving and connected surface cracks in overlying rock.When working face goes forward to the bottom of cheuches,the rock affected by mining gets incompact,and finally there is a obvious separation layer which is the most developed diversion fissure zone.When working face starts to go forwards against the slope,overlying rock step sink happens and the cracks below the cheuches are compacted gradually.The propelling of working face of 13#coal seam leads to caving of overlying rocks and when the range reach100m,caving is wider until connecting with above goaf,the rock in this goaf will fall again.Under the influence of this falling,the cracks also develops for the second time and the cracks will connect with the above goaf,leading to the further developing of cracks of 8#coal seam and surface cracks directly reach to 13#coal seam.With the continuous compelling of working face,overlying rock step falling happens,cheuches start to deform and diversion fissure zone becomes quite developing.when the range reach 200m,the cracks connect ground and the working face of 13#coal.?3?Using RFPA numerical method to simulate the results of the overlying rock mass acoustic emission and the vertical stress of key stratum changes with the different length of compelling,the dynamic process of overburden failure in cheches area is obtained,according to the overburden rock acoustic emission location and distribution of nucleation zone,we can predict the location of the water inrush risk and provide reference for water prevention and control.?4?Using COMSOL numerical calculation program to analyze the evolution of overlying rock seepage field in gully region with different advancing length under the condition of valley catchment,and according to similar simulation and RFPA numerical simulation of fracture distribution,to evaluated the water conductivity of gully region fracture zone.we can get the position of the water begin inrushing is that the working face enters to 120m,As well as the bottom of the downhill section.When the working face advances to 200m,the maximum water inrush velocity reaches2.43?10-3 m/s. |
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